Related Experiment Video

Updated: Jun 9, 2026

Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
14:05

Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes

Published on: September 19, 2013

Listeria monocytogenes PrsA2 is required for virulence factor secretion and bacterial viability within the host cell

Francis Alonzo1, Nancy E Freitag

  • 1Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612-7344, USA.

Infection and Immunity
|September 9, 2010
PubMed

Insights

The bacterial chaperone PrsA2 is crucial for Listeria monocytogenes survival within host cells, aiding virulence factor secretion. PrsA1 does not provide functional overlap, highlighting PrsA2's specific role in pathogenesis.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Host-Pathogen Interactions

Background:

  • Facultative intracellular bacteria like Listeria monocytogenes require precise regulation of virulence factors for host cell invasion.
  • Post-translocation secretion chaperones, such as PrsA1 and PrsA2 in L. monocytogenes, are implicated in protein folding and secretion at the bacterial membrane-cell wall interface.
  • PrsA2 is suggested to be specifically adapted for bacterial pathogenesis.

Purpose of the Study:

  • To investigate the roles of PrsA1 and PrsA2 in Listeria monocytogenes growth and protein secretion.
  • To determine the necessity of PrsA2 for bacterial viability within host cell cytosol.
  • To elucidate the functional relationship between PrsA1 and PrsA2.

Main Methods:

  • In vitro and in vivo growth assays for L. monocytogenes strains lacking PrsA1 or PrsA2.
  • Proteomic analysis of prsA2 mutant strains under conditions of activated virulence regulator PrfA.
  • Comparison of amino acid sequences and functional overlap between PrsA1 and PrsA2.

Main Results:

  • Neither PrsA1 nor PrsA2 was essential for L. monocytogenes growth in broth culture.
  • Optimal bacterial viability within host cell cytosol was dependent on PrsA2.
  • PrsA2 activity was critically required under conditions of PrfA activation, mimicking host cell infection.
  • No functional overlap was detected between PrsA2 and PrsA1 despite high sequence similarity.

Conclusions:

  • PrsA2 plays a critical role in Listeria monocytogenes pathogenesis, particularly within the host cell cytosol.
  • PrsA2 is essential for bacterial viability and virulence factor regulation during host cell infection.
  • PrsA1 and PrsA2 are functionally distinct, with PrsA2 uniquely adapted for infection-related processes.

More Related Videos

RNA Purification from Intracellularly Grown Listeria monocytogenes in Macrophage Cells10:42

RNA Purification from Intracellularly Grown Listeria monocytogenes in Macrophage Cells

Published on: June 4, 2016

Listeria monocytogenes Infection of the Brain05:02

Listeria monocytogenes Infection of the Brain

Published on: October 2, 2018

Related Concept Videos

Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Determinants of Bacterial Pathogenicity and Virulence01:20

Determinants of Bacterial Pathogenicity and Virulence

Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...
Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...
Gram-negative Bacterial Protein Secretion Systems01:17

Gram-negative Bacterial Protein Secretion Systems

Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
Colonisation of Pathogens01:25

Colonisation of Pathogens

Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...
Bacterial Translocation and Protein Secretion01:26

Bacterial Translocation and Protein Secretion

Bacterial protein secretion involves translocation systems to ensure proteins reach their designated locations, including the plasma membrane, periplasm, outer membrane, or the external environment. These translocation systems are vital for bacterial physiology, supporting processes like membrane assembly, enzymatic activity in the periplasm, and interactions with the external environment. The division of labor between Sec and Tat pathways ensures efficiency in handling proteins with diverse...